Did a long-running conflict over which religious upbringing was best for their
daughter lead to the breakdown of Hollywood’s most curious relationship?

Even by the standards of celebrity effusiveness, it was a cringingly embarrassing on-air declaration of love.

In an impressive imitation of a hyperactive child, Tom Cruise jumped up and down on the famous sofa of talk show queen Oprah Winfrey and professed his devotion for his new girlfriend, Katie Holmes.

That was seven years and countless red carpets and glossy magazine covers ago – a lifetime in showbusiness circles, and also, it turns out, for the marriage of Hollywood’s most curious couple sometimes known as “TomKat” for short.

For on Friday came the news that Holmes had filed for divorce – the final act for a union that had been as widely mocked as it was obsessively monitored.

At the time, Holmes’s husband was 2,600 miles away, working in Iceland on a new film called Oblivion. And he was apparently oblivious to her plans until shortly before her lawyers lodged the paperwork in New York.

It was an unwanted early birthday present for Cruise, who turns 50 on Tuesday. The couple have not been seen together for months, prompting speculation about the marriage. His refusal to leave the remote film set to celebrate his milestone birthday with his family was said to have been the final straw for his 33-year-old wife, with whom he has a six-year-old daughter, Suri.

But an underlying cause of the split seems to have been a crisis of faith for Holmes, over her husband’s devotion to Scientology.

Created in 1953 by pulp-fiction writer L Ron Hubbard, the Church of Scientology encourages believers to re-experience pain and trauma in their lives in order to rid themselves of its effects.

Often described as a cult, it also counts John Travolta, Kirstie Alley and Lisa Marie Presley among its high-profile followers.

Holmes, who was raised in a Roman Catholic, Mass-attending family in Ohio, had embraced the church’s strictures to marry Cruise, her heart-throb as a teenager (she had the Cocktail film poster, featuring him as a dashing bartender, on her wall). But she is said to have clashed with him over whether their daughter would be raised a Scientologist. Indeed, Holmes has reportedly applied for “primary residential custody” of the six year-old.

Prior to the couple’s lavish 2006 wedding, in an Italian castle with a star-studded guestlist that included David and Victoria Beckham, critics of Scientology ran a “Free Katie” campaign, with slogans including “Run, Katie, Run!”

The actor has since denied that Holmes was selected after he “auditioned” several younger stars – said to have included Penélope Cruz and Scarlett Johansson – for the role of his third wife.

In the intervening years, friends said Holmes had become increasingly disillusioned with Scientology. In 2009, she insisted that Suri attend a Roman Catholic kindergarten.

TMZ, the gossip news website, said: “Our sources say Katie has never been fully committed to Scientology, even though she has had ties with the church. We’re told the couple had been arguing over Suri – that she’s now of an age when Scientology becomes a significant part of her life.”

It is telling that Holmes chose to file for divorce in New York, where the couple have an apartment, rather than California, even though their marriage was registered there and is their primary home. The East Coast state does not tend to award joint custody to parents squabbling over how to raise a child. Their home state, on the other hand, favours joint legal custody.

In his statement, Holmes’s lawyer Jonathan Wolfe noted that “Katie’s primary concern remains, as it always has been, her daughter’s best interests”. Those words fuelled speculation that the split was over Suri’s future. Friends said that Holmes was also depressed as her career was stuttering while the Top Gun and Mission: Impossible star remains one of the most bankable names in Hollywood.

Best known as the star of teen drama Dawson’s Creek before she met Cruise, Holmes landed a major role in Batman Begins (2005), but the calls have since dried up, despite being one half of arguably the most glamorous married couple on the scene.

There have been other signs that all was not well in the world of TomKat. Just two weeks ago, Cruise was lauded as an “entertainment icon” by his peers at the legendary Manhattan showbusiness haunt, the Friars Club. The room was bursting to the seams with A-list stars, but the actor’s date for the night was Suri, not Katie. Holmes was in China for her new fashion business, he told interviewers, struggling to maintain his famous white-toothed grin. He was also without his wife for the recent London and US premieres of his current film, Rock of Ages, which has underperformed at the box office.

A month earlier, Holmes was reported to be furious about a raunchy magazine shoot to promote the movie in which her husband was entwined with two half-naked blonde models, one of them suggestively licking his face.

For her own part, Holmes has recently looked glum, tired and drawn, wearing little make-up and with signs of grey in her brown hair. It is a stark contrast to her ever-youthful, ever-beaming husband – and indeed to their daughter, who is regularly to be seen in high heels and striking pink attire, her mother’s sole companion.

kept separate bedrooms, so she can get a good night’s sleep away from Tom’s snoring.

Their domestic arrangements are further complicated by Tom’s sister, Cass Mapother, living in the couple’s Beverly Hills home, along with her three sons, and Tom’s adopted children Conor, 17, and 19-year-old Isabella, from his second marriage, to actress Nicole Kidman. Holmes was said to feel excluded and lonely. Her close friendship with Victoria Beckham, which emerged soon after David signed to LA Galaxy, ended when it became apparent that the Beckhams would not sign up to Scientology.

The end of Cruise’s third marriage undermines a campaign by “Team Tom” to portray the actor as a “regular guy”, and has prompted renewed speculation about his commitment to wedded life.

He split from his second wife, actress Nicole Kidman, with whom he had two adopted children, in 2001. His first marriage, to actress and fellow Scientologist Mimi Rogers, had ended after two years, in 1990.

Rogers later bemoaned that Cruise acted like a monk in the bedroom. “He thought that he had to be celibate to maintain the purity of his instrument, but my instrument needed tuning and we had to split,” she said.

Holmes and Cruise signed a pre-nuptial agreement that reportedly gives the actress $3 million for each year of marriage. But Cruise may offer her a bigger share of his fortune – estimated at about $275 million (£175 million) – to secure her silence about the split, following the example of Tiger Woods, who paid his wife Elin Nordegren about $100 million after reports emerged of his extramarital philandering.

RadarOnline, another gossip website, claimed that the relationship turned sour after Holmes became “sick” of her husband’s controlling ways. “When Katie first met Tom, she was blown away” a source close to the actress told the site. “She had idolised him as a child and here she was, with him, in person. Tom turned on the megawatt smile and the amazing charm that he is capable of exuding and Katie was totally caught up in it all.

“He whisked her off her feet – romance, love, private jets, shopping sprees, all the razzle dazzle that goes with being an A-lister. The next thing you know, she’s pregnant and then she’s getting married in this fairytale ceremony. She didn’t have time to breathe, let alone take stock of the situation.”

But then reality began to sink in. “Tom has always made all the decisions in their relationship,” said the website’s source. “After five years of this, Katie felt she was turning into the robot that the press always made her out to be. She’s got a great personality and she used to be feisty. She changed so much when she was with Tom. She became downtrodden and insipid.”

Yet only in May, Cruise was extolling the virtues of their relationship. He told Playboy magazine: “She is an extraordinary person, and if you spent five minutes with her, you’d see it. Everything she does, she does with this beautiful creativity.

“I like doing things like creating romantic dinners, and she enjoys that. I’m just happy, and have been since the moment I met her. What we have is very special.”

He sounded as enthusiastic then as he did in 2006 when he told another magazine: “I know I’m with the woman I want to spend the rest of my life with… I won’t let this woman get away.”

Married bliss may not be for ever. But for a Hollywood star, couch-jumping displays of love and adoring quotes live on for perpetuity.